Geometric Effects of Linear Friction Welding on Residual Stresses

Linear friction welding is a promising solid-state joining technology, which has been widely used for the manufacturing of blisks and preforms of complex components in aerospace engineering. As other welding processes, strong local heat input leads to the formation of high tensile residual stresses during linear friction welding. Numerical prediction of welding residual stresses is critical for the assessment of structure integrity. Compared to traditional welding, LFW includes unique processing variables that have potential influence on residual stresses distribution. For instance, presented research shows that applied pressure has significant effect on residual stresses. However, the geometric effects of components on residual stresses has not been investigated yet. One key attraction of LFW is to provide the possibility to manufacture preforms of complex parts with less raw material, thus, the welding interface with various cross-sections are inevitable. Based on validated finite element modeling, we try to further investigate the geometric effects on residual stresses and build the relationship between geometric effects and residual stress distribution. It deepens the understanding of residual stress evolution patterns of linear friction welding and potential optimizing directions.